Compared to Mars the moons of the gas giants have at least three major hurdles for long-term human habitation: their distance, with the trip there being around

Compared to Mars the moons of the gas giants have at least three major hurdles for long-term human habitation: their distance, with the trip there being around 6 years, the incredibly harsh planetary radiation belts the moons weave through, and ineffectiveness of solar energy that far away from the sun. I think we should try to overcome these hurdles, but getting humans out there is a much taller order than establishing a human presence on Mars.